Casting machine



Feb. 16 ,1926. I 1,573,518

- -A. KAUFMANN CASTING MACHINE Filed Sept. 22, 1925 Patented Feb. 16, 1926 UNITED STATES PATENT. orifice.

ALBERT KAUFMANN, OF- BERLIN, GERMANY.

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Application filed September 22, 1525. Serial No. 57,924.

ejected from a casting reservoir bya gas ,un-'

dsr pressure, said reservoir being charged from a. crucible through its discharge port.

The casting reservoir may be stationary or di'splaceable.

As atmospheric air is often or generally used as the fluid under pressure, and the molten metal is generally aluminium, the air which is in contact with the surface of the molten metal in the reservoir, 18 liable'to produce oxidation on the aluminium. An-

other drawback is that the compressed air or other gas causes whirling on the surface of the molten metal.

. These drawbacks are overcome in my in-' vention by placing -on the surface of the molten metal in the casting reservoir a float, for instance, a spherical or partly spherical body, the outer diameter of'which is substantially equal to the inner diameter of the casting reservoir and the specific gravity is such that the float, if spherical, is immersed in the molten metal as .far as its equatorial plane. v

The fioat or sphere is made from a mateiial which is not attacked by the pressure fluid employed or the molten metal. The float practically prevents contact of the'fluid with the surface of the molten metal as the diameter of the float is substantially equal to the inner diameter of the castingreservoir.

for instance, a sphereor part of asphere, and may, be solid or hollow, for instance, a solid globe-of a material such as porcelain, the specific gravity of which is not in excess of that of themolten metal. When the specific gravity of the material is not sufiicient, the float may be weighted so as to obtain the desired depth of immersion.

In some cases, it may be preferable to make the float from a material the specific gravity of which exceeds that of the molten The float may be of any suitableshape,

metal, for instance, steel. The section of the metal is so determined as to obtain the desired depth of immersion.

I prefer a float of spherical shape because this avoids any jamming of the float on the wall of the reservoir and also precludes the possibility of exposing a comparatively large surface of the molten metal to the ac' tion of the pressure fluid if the floatwhich in this case would not be a sphereassumes an inclined position. i Preferably, I heat the pressure fluid which.

is supplied to the machine by a compressor or the like, by arranging the pipe line in the immediate vicinity of the crucible, or by passingit around said crucible. in the form of a coil.

In the drawings, two constructions embodying my invention are illustrated by way of example.

In the drawings, 1 a

Fig. l'is an elevation, partly in section, of a unachine the float of which is constituted by a full sphere,

Fig. 2 is a similar elevation showing a float constituted byabout two thirds of a sphere,

Fig.3 is a plan View o'fthe machine.

Referring now'to'the drawings, a is the crucible which is provided with a discharge valve b and adapted to cooperate with a swivelling and substantially-U-shaped casting reservoir 0. However, I desire it to be understood that the construction of the machine as such is no part of, and has no hearing on, my invention.

1 In the tubular portion of the casting reservoir, c, which is filled with molten metal 0?, a float is. inserted which in the modification shown in Fig. 1 is a hollow sphere e of a suitable metal, for instance, steel, the wall section of which is so determined that it is immersedin the molten metal as far as its equatorial plane. The clearance between the sphere and the tubular portion 0' is as small as practicable so as to permit the sphere e to move freely in the tube 0'.

Fluid under pressure is supplied to 0' through a pipe 7 to which is connected a pipe 9 which is in contact with part of the wall of the crucible a so that the air in the pipe is heated.

The fluid, compressed air or the like, acts only on the sphere and is practically excluded from the surface of the molten metal,

Referring now to Fig. 2, this is similar to Fig. 1 but the float e is only part of a sphere. Theoretically, it might be a hemisphere but it is preferable to extend it slightly beyond its equator, as shown. The weight of this sphere is such, as in the case of the full sphere, that it is immersed in the liquid metal as far as the equator.

If the fluid under pressure is heated as described by passing the pipe 9 around part of the crucible a as shown or by coiling it around the same, the molten metal in the casting reservoir is not refrigerated by the fluid.

I claim:

1. Casting machine comprising a casting reservoir, means for supplying fluid under pressure to said reservoir, and a float'in said reservoir which is adapted to rest on, and partly to be immersed in, the molten metal in said reservoir.

2. Casting machine comprising a casting reservoir, means for supplying fluiduinder pressure to said reservoir, and a weighted float in said reservoir which is adapted to rest on, and partly to be immersed in, the molten metal in said reservoir.

3. Casting machine comprising a casting reservoir, means for supplying fluid under pressure to said reservoir, and a spherical float in said reservoir which is adapted to rest on, and partly to be immersed in, the molten'metal insaid reservoir.

4. Casting machine comprising a casting reservoir, means for supplying fluid under pressure to said reservoir, and a float in said reservoir which is partly shaped on a sphere and adapted to rest on, and partlyto be immersed in, the molten metal in said reservoir.

5. Casting machine comprising a casting reservoir, means for supplying fluid under pressure to said reservoir, and a sphere of a diameter substantially equal to the inside diameter of said reservoir, said sphere being adapted to rest on the molten metal in said reservoir and to be immersed therein substantially to its equatorial plane.

6. Casting machine comprisinga casting reservoir, means for supplying fluid under pressure to said reservoir, and a solid sphere from a material the specific gravity of which does not exceed that of the molten metal, said sphere being adapted to rest on, and partly immersed in, the molten metal in said reservoir.

7. Casting machine comprising a casting,

reservoir, means for supplying fluid under pressure to said reservoir, and a hollow sphere from a material the specific gravity of which exceeds that of the molten metal, said sphere being adapted to rest on, and partly immersed in, the molten metal in said reservoir.

8. Casting machine comprising a casting reservoir, a crucible adapted to be connected with said reservoir, a pipe line arranged adjacent to said crucible .for supplying gas under pressure to said reservoir, and a float in said reservoir which is'ad'apted to be immersed in, and to rest on, the molten metal in said reservoir.

In testimony whereof I have signed my name to this specification.

ALBERT KAUEMANN. 

